Fix thread citations rendering as "Thread no longer available"

apps/mobile/src/lib/enrichedLinkPresentation.test.ts

@@ -149,4 +149,16 @@ describe("Enriched link presentation", () => {
     ]);
     expect(threadChipTargets(here, "No links here.")).toEqual([]);
   });
+
+  it("finds thread links with angle-bracketed destinations", () => {
+    const here = "env-here" as EnvironmentId;
+    expect(threadChipTargets(here, "See [A](<t3-thread://v2/env-here/thread_a>).")).toEqual([
+      {
+        href: "t3-thread://v2/env-here/thread_a",
+        environmentId: here,
+        threadId: "thread_a",
+        link: true,
+      },
+    ]);
+  });
 });

apps/mobile/src/lib/enrichedLinkPresentation.ts

@@ -62,7 +62,7 @@ export function threadChipTargets(
 ): ReadonlyArray<ThreadChipTarget> {
   const targets = new Map<string, ThreadChipTarget>();
   if (hasThreadLinks(markdown)) {
-    for (const [, href = ""] of markdown.matchAll(/\]\((t3-thread:\/\/v[12]\/[^\s)]+)\)/g)) {
+    for (const [, href = ""] of markdown.matchAll(/\]\(<?(t3-thread:\/\/v[12]\/[^\s>)]+)>?\)/g)) {
       const link = parseThreadLinkHref(href);
       if (link) {
         targets.set(href, {

apps/mobile/src/state/entities.ts

@@ -1,4 +1,5 @@
 import { useAtomValue } from "@effect/atom-react";
+import { useEffect } from "react";
 import { deriveReportedModelSelection } from "@t3tools/client-runtime/state/thread-execution";
 
 import { appAtomRegistry } from "./atom-registry";
@@ -34,7 +35,7 @@ import { projectGlyphImageAtom, projectGlyphKey } from "../native/ProjectChipIco
 import { projectFaviconUrlAtom } from "./assets";
 import { environmentProjects } from "./projects";
 import { environmentServerConfigsAtom, serverEnvironment } from "./server";
-import { environmentThreadDetails, environmentThreadShells } from "./threads";
+import { environmentThreadDetails, environmentThreadShells, threadFamilies } from "./threads";
 
 const EMPTY_PROJECT_ATOM = Atom.make<EnvironmentProject | null>(null).pipe(
   Atom.withLabel("mobile-project:empty"),
@@ -208,11 +209,27 @@ export function useSideChats(ref: ScopedThreadRef) {
 }
 
 export function useLiveThreadLinkLabels(markdown: string, environmentId: EnvironmentId): string {
+  const refs = hasThreadLinks(markdown) ? threadLinkRefs(markdown, environmentId) : [];
   const titles = useAtomValue(
-    hasThreadLinks(markdown)
-      ? threadLinkTitlesAtom(JSON.stringify(threadLinkRefs(markdown, environmentId).map(threadKey)))
-      : EMPTY_THREAD_LINK_TITLES_ATOM,
+    refs.length === 0
+      ? EMPTY_THREAD_LINK_TITLES_ATOM
+      : threadLinkTitlesAtom(JSON.stringify(refs.map(threadKey))),
   );
+  // Shells leave out idle subagent children and older settled threads, so a cited thread the
+  // shell lacks is read with its family until it lands; only a settled empty read proves it gone.
+  const missingKey = JSON.stringify(
+    refs.filter((ref) => !titles.has(threadKey(ref))).map(threadKey),
+  );
+  // oxlint-disable-next-line t3code/no-unreasoned-state-sync -- mounts family reads for cited threads the shell omits while this message shows them
+  useEffect(() => {
+    const releases = (JSON.parse(missingKey) as ReadonlyArray<string>).map((key) => {
+      const ref = scopeThreadRef(...decodeThreadKey(JSON.parse(key)));
+      return threadFamilies.mount(appAtomRegistry, ref.environmentId, ref.threadId);
+    });
+    return () => {
+      for (const release of releases) release();
+    };
+  }, [missingKey]);
   return relabelThreadLinks(markdown, environmentId, (ref) => titles.get(threadKey(ref)));
 }
 

apps/web/src/components/chat/MarkdownThreadLink.tsx

@@ -1,3 +1,4 @@
+import { useEffect } from "react";
 import { scopeThreadRef } from "@t3tools/client-runtime/environment";
 import type { EnvironmentId } from "@t3tools/contracts";
 import {
@@ -8,7 +9,9 @@ import {
   unknownThreadLinkLabel,
 } from "@t3tools/shared/threadLinks";
 
+import { appAtomRegistry } from "../../rpc/atomRegistry";
 import { useThreadRefs, useThreadShell } from "../../state/entities";
+import { threadFamilies } from "../../state/threads";
 import { UnresolvedChip } from "../contextChipParts";
 import { ThreadContextChip } from "../ThreadContextChip";
 
@@ -25,6 +28,17 @@ export function MarkdownThreadLink(props: {
     written === null && decodedId !== null ? scopeThreadRef(environmentId, decodedId) : null,
   );
   const local = written ?? decoded;
+  // Shells leave out idle subagent children and older settled threads, so a cited thread the
+  // shell lacks is read with its family until it lands; only a settled empty read proves it gone.
+  const missingThreadId = local === null ? (decodedId ?? props.link.threadId) : null;
+  // oxlint-disable-next-line t3code/no-unreasoned-state-sync -- mounts the family read for a cited thread the shell omits while this link shows it
+  useEffect(
+    () =>
+      missingThreadId === null
+        ? undefined
+        : threadFamilies.mount(appAtomRegistry, environmentId, missingThreadId),
+    [environmentId, missingThreadId],
+  );
   const guess = local === null && props.link.environmentId === null;
   const refs = useThreadRefs(guess);
   const remote = useThreadShell(guess ? guessThreadLinkRef(props.link, refs) : null);

packages/shared/src/threadLinks.test.ts

@@ -102,6 +102,21 @@ describe("thread links", () => {
     ).toBe("[There](t3-thread://v2/there/t1) and [Here](t3-thread://v2/local/t1)");
   });
 
+  it("reads an angle-bracketed destination as the labeled link, not an autolink", () => {
+    const title = titlesIn({ local: { t1: "Here" }, there: { t1: "There" } });
+    expect(
+      relabelThreadLinks(
+        "[old](<t3-thread://v2/there/t1>) and [older](<t3-thread://v2/local/t1>)",
+        local,
+        title,
+      ),
+    ).toBe("[There](t3-thread://v2/there/t1) and [Here](t3-thread://v2/local/t1)");
+    expect(
+      relabelThreadLinks("[Kept label](<t3-thread://v2/local/t1>)", local, () => undefined),
+    ).toBe("Kept label");
+    expect(threadLinkRefs("[a](<t3-thread://v2/there/t2>)", local)).toEqual([ref("there", "t2")]);
+  });
+
   it("turns a v2 link it cannot resolve into plain text, never the raw link", () => {
     expect(
       relabelThreadLinks(

packages/shared/src/threadLinks.ts

@@ -6,8 +6,9 @@ export const THREAD_LINK_PROTOCOL = "t3-thread";
 const V1_PREFIX = `${THREAD_LINK_PROTOCOL}://v1/`;
 const V2_PREFIX = `${THREAD_LINK_PROTOCOL}://v2/`;
 // Code comes first in the alternation so a link written inside a code span or fence is skipped.
+// A labeled link's destination may be angle-bracketed, as CommonMark allows: [label](<href>).
 const THREAD_LINK_OUTSIDE_CODE =
-  /(?<fence>(`{3,}|~{3,})[\s\S]*?(?:\2|$))|(?<span>(`+)[^\n]*?\4)|\[(?<label>[^\]\n]*)\]\((?<href>t3-thread:\/\/v[12]\/[^\s)]+)\)|<(?<autolink>t3-thread:\/\/v[12]\/[^\s<>]+)>/g;
+  /(?<fence>(`{3,}|~{3,})[\s\S]*?(?:\2|$))|(?<span>(`+)[^\n]*?\4)|\[(?<label>[^\]\n]*)\]\(<?(?<href>t3-thread:\/\/v[12]\/[^\s>)]+)>?\)|<(?<autolink>t3-thread:\/\/v[12]\/[^\s<>]+)>/g;
 
 const decodeThreadId = Schema.decodeUnknownOption(ThreadId);
 const decodeEnvironmentId = Schema.decodeUnknownOption(EnvironmentId);